Games built using the OpenRA engine are known as “mods”. The OpenRA development team maintain the three official mods that can be downloaded from this website, but many more are developed and maintained by the OpenRA community.
Tiberian Dawn
An alliance of nations fights to protect Europe and northern Africa from a mysterious terrorist organization and the valuable but toxic alien mineral, Tiberium, that is slowly spreading over the world.
The Tiberian Dawn mod focuses on fast and fluid play, taking heavy influences from modern RTS games with features like multiple-queue production.
Red Alert
In a world where Hitler was assassinated and the Third Reich never existed, the Soviet Union seeks power over all of Europe. Allied against this Evil Empire, the free world faces a Cold War turned red hot.
The Red Alert mod focuses on strategy, providing a range of units and tactics to conquer the land, sea, and air.
Dune 2000
Three great houses fight for the precious spice melange. He who controls the spice controls the universe! Establish a foothold on the desert planet Arrakis, where your biggest threat is the environment.
The Dune 2000 mod currently focuses on providing an experience that is authentic to the original game.
Tiberian Sun
The next major goal for OpenRA is to support the second generation of Command & Conquer games, starting with Tiberian Sun.
The game engine features to support Tiberian Sun are still in development. The mod is not included with the OpenRA installer, but the source code is available in our GitHub repository. Please note that we do not provide support for incomplete development builds.
OpenRA is designed as a general purpose RTS game engine with strong modding support. The OpenRA Mod SDK provides tools to develop and release your own projects. Each new OpenRA release brings many improvements and fixes created for, and by, the modding community. A collection of community-built mods and games can be found on OpenRA's ModDB page.
In a world where Hitler was assassinated and the Third Reich never existed, the Soviet Union seeks power over all of Europe. Allied against this Evil Empire, the free world faces a Cold War turned red hot.
Red Alert 2 introduced the soviet union to my child brain who barely knew English. Coming from a Muslim country, I already knew the allies were bad so 10 year old me assumed the soviet union are the good guys in the red alert universe. It's not all bad haha. Looking back at the red alert cut scenes, they really did Stalin dirty
The world is your oyster. You can make all sorts of mods with any story and atmosphere.
It sounds like you may be interested in potentially making a mod (or you are just interested in someone else making one, in which case the following resources should be helpful to such a person). You will probably need to learn C#, PowerShell, shell, etc. and work with this SDK:
https://github.com/OpenRA/OpenRAModSDK
You can look at community mods here to find examples to learn from and see what is possible:
https://www.moddb.com/games/openra/mods
You can click on one of the mods and potentially find their own git repository, such as this one: OpenE2140
To prove my point that you can make a mod with your own story and atmosphere, this mod is a (literal) bug swarm strategy game: OpenSA
For the mod itself, you will be mostly programming in C# and sometimes another language if you decide to use one (it seems with this particular engine, modders tend to either use just C# or C# and Lua). Shell, make, and other languages are typically used for the packaging and installation/generation/compilation/etc. scripts/tools of the mod.
I'd like to see more, but the only ones that I know of are red eclipse (kind of like halo), 0AD (kind of like age of empires), and minetest (Minecraft but really made so that each server can have any number of ridiculous difference in gameplay because of mods).
Oh, OK. So this is more like the “potential “for more games to be created on a sort of platform. I was just expecting to see a list. Thanks for clarifying. 
No, there is a list: https://lemmygrad.ml/comment/2278718
This is just an open source engine for the classic Command & Conquer games. You need to supply discs/isos to be able to play the games fully--similar to open source ports like GZDoom/PrBoom for Doom/Quake/etc. and OpenMW for The Elder Scrolls III: Morrowind.
What other games? I only see RA
https://www.openra.net/about/
The OpenRA Games (aka Mods)
😐
I mean, that's the game for you. It's over the top anti-soviet chauvinism in such a theatrical way that it loops back around to being hilarious
SPACE
Red Alert 2 introduced the soviet union to my child brain who barely knew English. Coming from a Muslim country, I already knew the allies were bad so 10 year old me assumed the soviet union are the good guys in the red alert universe. It's not all bad haha. Looking back at the red alert cut scenes, they really did Stalin dirty
Being open source, we can write our own mods, correct? (not that I have the skills...)
yep
So a mod could be written with an anti-colonial, anti-imperial atmosphere
The world is your oyster. You can make all sorts of mods with any story and atmosphere.
It sounds like you may be interested in potentially making a mod (or you are just interested in someone else making one, in which case the following resources should be helpful to such a person). You will probably need to learn C#, PowerShell, shell, etc. and work with this SDK:
https://github.com/OpenRA/OpenRAModSDK
You can look at community mods here to find examples to learn from and see what is possible:
https://www.moddb.com/games/openra/mods
You can click on one of the mods and potentially find their own git repository, such as this one: OpenE2140
This mod used Lua as well: Generals Alpha
To prove my point that you can make a mod with your own story and atmosphere, this mod is a (literal) bug swarm strategy game: OpenSA
For the mod itself, you will be mostly programming in C# and sometimes another language if you decide to use one (it seems with this particular engine, modders tend to either use just C# or C# and Lua). Shell, make, and other languages are typically used for the packaging and installation/generation/compilation/etc. scripts/tools of the mod.
I'd like to see more, but the only ones that I know of are red eclipse (kind of like halo), 0AD (kind of like age of empires), and minetest (Minecraft but really made so that each server can have any number of ridiculous difference in gameplay because of mods).
Oh, OK. So this is more like the “potential “for more games to be created on a sort of platform. I was just expecting to see a list. Thanks for clarifying. 
No, there is a list: https://lemmygrad.ml/comment/2278718
This is just an open source engine for the classic Command & Conquer games. You need to supply discs/isos to be able to play the games fully--similar to open source ports like GZDoom/PrBoom for Doom/Quake/etc. and OpenMW for The Elder Scrolls III: Morrowind.
Thanks!
Here's a start:
I mentioned some games on Lemmygrad a few months ago:
https://lemmygrad.ml/comment/605845